Aqueous level abatement profiles of intracameral antibiotics: A comparative mathematical model of moxifloxacin, cefuroxime, and vancomycin with determination of relative efficacies.

PURPOSE: To create a model of the abatement profiles of the three most commonly employed endophthalmitis prophylaxis intracameral (IC) antibiotics-cefuroxime, vancomycin, and moxifloxacin-to enable comparison of their durations of efficacy against common endophthalmitis pathogens.

SETTINGS: Humber River Hospital and The Eye Foundation of Canada, Toronto, Ontario, the University of Toronto, Ontario, and McGill University, Montreal, Quebec, Canada.

DESIGN

Literature review, as well as review of our clinical experience with 4797 consecutive cases with IC vancomycin, followed by 9185 consecutive cases with IC moxifloxacin.

METHODS

A detailed review of the prophylactic antibiotic literature was performed. Exponential decay models of the selected IC antibiotics were updated from previous work by the study authors with decay constants adjusted to agree with the available published objective data.

RESULTS

The graphs generated by the study data demonstrate the relative duration of IC bactericidal activity of moxifloxacin, cefuroxime, and vancomycin. They suggest that at present, IC moxifloxacin, when administered in appropriate doses, is the most effective agent in preventing postoperative endophthalmitis. Unlike vancomycin and cefuroxime, bacterial resistance to moxifloxacin is dose-dependent, and it is overcome in the vast majority of cases with doses that can safely be achieved intracamerally. The graphs can serve as a useful tool to assess the expected efficacy of each antibiotic in reference to local pathogen resistances.

CONCLUSION

The model shows IC moxifloxacin, cefuroxime, and vancomycin durations of bactericidal efficacy post-cataract surgery, which correlate well with the published objective data.